DESCRIPTION: The applicant proposes to develop and test a new general computer simulation algorithm that can be used for modeling the behavior of physiological systems with components of different material properties (multiphysical problems). Examples are blood flow, aqueous flow, joint mechanics. Solid-fluid interactions pose challenges too great for traditional approaches to computer simulation. The applicant proposes to apply a new algorithm, called first-order system least-squares (FOSLS). FOSLS transforms a mathematical problem into a larger but simpler form, which allow existing high-powered numerical methods to solve the problem much faster than the original form permits. The applicant describes how his method could clarify questions of possible interaction between aqueous humor flow and a deformable iris.